Committee Chair

Newman, James C., III

Committee Member

Anderson, W. Kyle; Sreenivas, Kidambi; Webster, Robert S.; Belinskiy, Boris

Department

Dept. of Computational Engineering

College

College of Engineering and Computer Science

Publisher

University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)

Abstract

A time-dependent adjoint approach for obtaining sensitivity derivatives for shape optimizations of acoustic metamaterials and phononic crystals is presented. The gradient-based design procedure is suitable for large numbers of design variables, and results are shown on achieving effective material properties with a unit cell and the broadband noise reduction with periodic arrays of cylinders. The acoustic wave propagation problem is solved in the time-domain using a Streamline Upwind/Petrov Galerkin formulation. Topology parameterization is accomplished using the homogenization method, and shape optimization is subsequently used afterwards to refine the geometries. Surface parameterization is accomplished using control grids, which are based on a Laplace equation. The combined strategy is compared with penalty-based topology optimization. Furthermore, the proposed topology optimization is also conducted on the design of a broadband acoustic cloaking device.

Acknowledgments

First, the author would like to thank his wife, Chao Wu, for encouragements during the work. It was her supports that made the author focus on the research and overcome the difficulties. Many people have given great help in this project. The author would like to give special thanks to Drs. James Newman and Kyle Anderson for providing invaluable advice. Last but not least, thanks are also given to the SimCenter for providing the author the academic training as well as the computational tools to complete the research for this project.

Degree

Ph. D.; A dissertation submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Doctor of Philosophy.

Date

12-2016

Subject

Broadband communication systems; Computer simulation

Keyword

Adjoint based sensitivity analysis; Acoustic metamaterial; Phononic crystal; Broadband optimization

Document Type

Doctoral dissertations

Extent

xii, 78 leaves

Language

English

Rights

Under copyright.

License

http://creativecommons.org/licenses/by/3.0/

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